// 修剪搜索二叉树
// 测试链接 : https://leetcode.cn/problems/trim-a-binary-search-tree/
public class TrimBinarySearchTree {
    public static class TreeNode {
        public int val;
        public TreeNode left;
        public TreeNode right;
    }

    public TreeNode trimBST(TreeNode root, int low, int high) {
        if(root == null){
            return null;
        }
        if(root.val < low ){
            return trimBST(root.right,low,high);
        }
        if(root.val > high){
            return trimBST(root.left,low,high);
        }
        root.left = trimBST(root.left,low,high);
        root.right = trimBST(root.right,low,high);

        return root;
    }
}
